Electric switch



y 1930- J. .1. HOGAN 1,758,793

ELECTRIC SWITCH Filed April 30, 1928 IN 5 N TOR JAY J. HOGAN Patented .May 13, 1930 PATENT OFFICE JAY J. HOGAN, OF STRATFORID, CONNECTICUT,

ASSIGNOR TO THE BRYANT ELECTRIC COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF CONNECTICUT nnnc'rnrc swm'o'n App1ication filed April 30,

This invention relates to an electric switch, and more particularly to contacts therefor, in which there is relative movement of the contacts after engagement. The object of the invention is to produce amovable contact which makes a sliding or rubbing surface engagement with the fixed contact when the two are being brought into engagement, but provides a rolling contact when the contact is being broken.

The drawing is an elevation of a knife switch embodying the invention.

In switch contacts where there is relative movement of the surfaces after initial engagement, the surfaces are by that rubbing action kept clean and a good contact is made, but the pressure necessary to produce this rubbing contact makes it hard to open the switch. To overcome this dilficulty the roller type of contact has been used in which the moving contact has a roller mounted at its end adapted to engage the fixed contact. This roller contact has no rubbing action, andconsequently does not keep the contact clean. According to the present invention there is a rubbing or brushing contact when closing the switch, but a roller contact when opening the switch.

Referring to the drawings, the knife blade 1 is pivoted on a support. 2 which is operated by the handle 3. The support 2 has a wire 4 connected thereto. The fixed contact 5 has the other wire 6 connected thereto, the

fixed contact consisting in this case of a .resilient spring blade mounted with its face toward the roller. According to this invention there is a roller 7 mounted on theend of the knife blade 1 and adapted to form a contacting surface with the fixed contact. Mounted beside this roller and revolving therewith is a ratchet 8 engaged by a spring V 9 riveted to the knifeblade 1. This spring- 1 9 and-the teeth of the ratchet wheel 8 engage each other in such manner as to permit the roller 'to revolve in a counterclockwise direction,- as shown in the drawing, but to prevent rotation in opposite direction. It will be apparent, when the handle 3 is operated to close the' contact, the-roller 7 will be held from revolving bymeans of a ratchet 8, and the 1928; Serial No. 278,939.

spring 9, and a rubbing contact will ensue. However, when it is desired to open the switch the spring 9 is sufficiently weak to permit the roller to turn freely, thus insuring an easy opening of the switch.

It will be noted that by this construction all the-advantages of boththe rubbing and roller contacts are obtained. The contacts are brushed clean and easy opening of the switch is obtained and a new contact surface is provided on the roller every time the switch is opened. It will be obvious that this simple device may be embodied in many types of electric switch. Therefore I do not limit myself in any way as to the type of switch in which it may be used.

I claim- 1. An electric switch having a fixed contact and a moving contact adapted to be in engagement therewith for a part of its movement, said contacts being adapted to make a rubbing surface engagement with each rection.

preventing rotation of said roller in one di- 3. An electric switch having a contact surrubbing contact therewith when the switch is being closed, and rolling contact therewith when the switch is being opened.

'face and aroller contact adapted to make- 4. An electric switch having a fixed contact and a moving contact comprising a blade, 1

the roller on said blade adapted to engage said fixed contact, and a ratchet and pawl adapted" to revent rotation of said roller when the switch is being closed, but to ermit turning of said roller when the swltch is being opened. v

In testimony whereof I have signed my name to this specification.

JAY J. HOGAN. 

